diff --git a/libcontainer/generic_error_test.go b/libcontainer/generic_error_test.go
index 292d2a36..8fbdd4d3 100644
--- a/libcontainer/generic_error_test.go
+++ b/libcontainer/generic_error_test.go
@@ -12,3 +12,38 @@ func TestErrorDetail(t *testing.T) {
 		t.Fatal(derr)
 	}
 }
+
+func TestErrorWithCode(t *testing.T) {
+	err := newGenericError(fmt.Errorf("test error"), SystemError)
+	if code := err.Code(); code != SystemError {
+		t.Fatalf("expected err code %q but %q", SystemError, code)
+	}
+}
+
+func TestErrorWithError(t *testing.T) {
+	cc := []struct {
+		errmsg string
+		cause  string
+	}{
+		{
+			errmsg: "test error",
+		},
+		{
+			errmsg: "test error",
+			cause:  "test",
+		},
+	}
+
+	for _, v := range cc {
+		err := newSystemErrorWithCause(fmt.Errorf(v.errmsg), v.cause)
+
+		msg := err.Error()
+		if v.cause == "" && msg != v.errmsg {
+			t.Fatalf("expected err(%q) equal errmsg(%q)", msg, v.errmsg)
+		}
+		if v.cause != "" && msg == v.errmsg {
+			t.Fatalf("unexpected err(%q) equal errmsg(%q)", msg, v.errmsg)
+		}
+
+	}
+}